(Update)Can I get some advice on boiler/storage drawings?

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goosegunner

Minister of Fire
Oct 15, 2009
1,469
WI
I have attached two drawings for my econoburn with 1000 gallon lp tank for storage.

One uses the same ports for charging/load and boiler return/ Load return.

The other one uses one end of the tank for boiler and the other for the load.

I am not sure where to put the econoburn recirc, I think I can delete it but the controls will have to be altered. I purchased a Danfoss for return protection. I am going get the boiler going and then add the storage, So I am adding valves to bypass the tank.


thanks

gg
 

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Hydraulically, looks kinda like the 'Simplest Pressurized' design. I assume there's another circulator for the loads.

I think you'll want to move the circ in the drawing to the left of the recirc loop, otherwise it will draw backwards through the Danfoss.

It would be good if both circs were multispeed (or variable speed) so that you can balance flows.
 
I have grunfos 3 speed circs.

My load is in 120' away in my attached garage. I have a primary/secondary manifold with closely spaced T's. I can switch the primary pump to run only on call for heat from any of my zones on the Taco zone controller.

One thing I am not sure of is how it will work when running without storage. Say the boiler drops below 150 and the boiler circulator shuts off. If I get a call for heat in the house will my load pump struggle to pull water through the boiler circulator? I won't have my storage hooked up right away so It won't be able to draw from that.

attached is a picture of my load end in the attached garage.

gg
 

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nofossil said:
I think you'll want to move the circ in the drawing to the left of the recirc loop, otherwise it will draw backwards through the Danfoss.

Good catch! I see it now. Like I said, I am not real sure where to put that one. The Econoburn manual says it is on at 80 and off at 150 degrees.

From what I understand you want to pull through the Danfoss right?

gg
 
goosegunner said:
nofossil said:
I think you'll want to move the circ in the drawing to the left of the recirc loop, otherwise it will draw backwards through the Danfoss.

Good catch! I see it now. Like I said, I am not real sure where to put that one. The Econoburn manual says it is on at 80 and off at 150 degrees.

From what I understand you want to pull through the Danfoss right?

gg

The Econoburn uses a circ for bypass (inlet temp protection). With the Danfoss you don't need it. I'm assuming the circ above the boiler is your boiler circulator. If not, ignore everything else I'm about to say.

You want to pull through the Danfoss from inlets to outlet, not the other way around. On mine, I have the circ right next to the boiler inlet. With higher power circulators, there's some advantage (less risk of cavitation) to having the circ just upstream from the expansion tank connection, which is usually combined with an air separator somewhere near the boiler outlet. You probably want something like this:

boiler outlet ----- expansion tank connection ------->circ>---------- recirc tee to Danfoss -------------->storage and loads
 
[/quote]

The Econoburn uses a circ for bypass (inlet temp protection). With the Danfoss you don't need it. I'm assuming the circ above the boiler is your boiler circulator. If not, ignore everything else I'm about to say.

You want to pull through the Danfoss from inlets to outlet, not the other way around. On mine, I have the circ right next to the boiler inlet. With higher power circulators, there's some advantage (less risk of cavitation) to having the circ just upstream from the expansion tank connection, which is usually combined with an air separator somewhere near the boiler outlet. You probably want something like this:

boiler outlet ----- expansion tank connection ------->circ>---------- recirc tee to Danfoss -------------->storage and loads[/quote]

Yes, the circ above the boiler would be the boiler circulator. I put it there again, trying to determine how this thing will actually flow. The book says controler works like this;

Recirculation loop pump will turn on at 80 and off at 150

Boiler pump will turn on at 150

It also states that if you use storage, you must add a mixing valve. Other members on the site have informed me previously. Econoburn told me the recirc can be deleted but controls need to be changed.

I will delete the recirc loop pump it will simplify the system. I will have no water movement until sensor hits 150, are other systems set up that way?

Any advice on which storage tank connections would be best?

gg
 
My EKO as delivered didn't ciculate any water until the outlet temp reached the setpoint (160 on the EKO). Shouldn't be a problem as long as the outlet temp sensor is close to the boiler or in the water jacket. Probably is important to make sure your installation meets Econoburn's requirements - don't want to void warranty even if it's a valid install.

As far as tank connections, using separate connections pretty much ensures that you won't get any ghost flow through the boiler. You'll want to use large plumbing near the tank so that the water coming in is moving slowly and won't mix the tank contents. Visualize the situation where your storage and house are cold and you've just started a fire. You'd like the hot water from the boiler to flow straight to the loads without having to heat the tank first. If you can avoid inducing too much tank turbulence, you can get a this layer of hot water flowing across the top of the tank from the boiler to the loads without having to heat much of the storage water.

The approach in the 'Simplest Pressurized Storage' sticky is to use tees so that you can heat the loads without involving storage at all. Hydraulically equivalent if large / low restriction plumbing is used for the near-storage components. If there's and flow restriction in and out of storage with the single port approach, you can get ghost flow through your boiler when you're trying to get heat from storage.
 
Ok, sounds like either way would work, and using the separate boiler, load ports helps eliminates ghost flow. I had planned on using 1-1/2" copper for the boiler supply/return and then reducing down to 1-1/4" copper for the load to logstor underground. My house manifold is 1" copper. Lines to forced air furnace is 1" pex. I can still get heat a 130 degrees but barely.

I heat my pool in the summer. In that situation is it better to have Load return to the tank or back to the boiler? I can get a pretty big delta T off the pool exchanger, 50 degrees if I give it all the pool flow.

gg
 
I am using a similiar setup on my eononburn 150. I place the main circulator upstream of the bypass loop. The need for the circulator pump is eliminated by using the mixing valve. The Danfoss valve is in the same location and is configured to open at 140 and to be fully open at 158F. When the temperature is below 140 most flow is directed throught the bypass and once the temperature rises to above 140 flow will be brought from the rest of the system. The wiring is simple the pump (power) is wired to both the circulator relay and the main pump relay. As a result the pump will always be requested. The main circulator feeds the tanks and a second circulator is used to draw heat for the house when the boiler is firing or when in thermal storage. In thermal storage mode I am relying on the Danfoss valve to eventually close to prevent flow from circulating through the bypass - otherwise I will add a check valve. This is probably not an issue with the configuration of the thermal storage and the relative flow resitance through the boiler relative through the thermal storage. I will be firing this week - can let you know how it works out.

Regards,

Steve
 
heat4steve said:
I am using a similiar setup on my eononburn 150. I place the main circulator upstream of the bypass loop. The need for the circulator pump is eliminated by using the mixing valve. The Danfoss valve is in the same location and is configured to open at 140 and to be fully open at 158F. When the temperature is below 140 most flow is directed throught the bypass and once the temperature rises to above 140 flow will be brought from the rest of the system. The wiring is simple the pump (power) is wired to both the circulator relay and the main pump relay. As a result the pump will always be requested. The main circulator feeds the tanks and a second circulator is used to draw heat for the house when the boiler is firing or when in thermal storage. In thermal storage mode I am relying on the Danfoss valve to eventually close to prevent flow from circulating through the bypass - otherwise I will add a check valve. This is probably not an issue with the configuration of the thermal storage and the relative flow resitance through the boiler relative through the thermal storage. I will be firing this week - can let you know how it works out.

Regards,

Steve

Did Econoburn tell you to wire it that way?

Are you charging the tank and supplying the load from the same port?

gg
 
I did not ask econoburn about wiring. The pumps are run through a relay which toggles between the circulator pump and the main pump. If you look at the wiring diagram for the econoburn the relay is fed with power through a 5 amp circuit breaker at terminal 11 and feeds either 14 (the circulator pump) when not energized or 12 (the primary pump) when the relay is energized. By hooking these connections to the single pump the pump will always operate. Note whenever the lighted swicth is turned on one of the lines is powered. Essentially the need for the relay is uncessary terminal 11 and the pump terminal could be directly wired. The need for the circulator pump makes no sense to me if a mixing valve is needed and note that Econoburn recommends use of a mixing valve. I posted this question back in November on this forum if you want to see more opinions. In addition, Mark at econoburn agreed with this assessment.

Concerning storage, I have two propane tanks stacked on top of each other with the top tank receiving the boiler supply. Just upstream of this location is a tee which the house supply draws off when needed. When the boiler is in operation the flow through the tanks will be from top to bottom. When heating with thermal storage the flow is in reverse - similar to the simple pressurized storage. Again my concern is that flow through the bypass may occurr when transitioning to heating with thermal storage until the Danfoss valve closes. From your diagram I think the flow would flow preferentially through the tank when heating with thermal storage.

I used 1-1/4" cooper and black pipe for my plumbing - could not bare spending for 1-1/2".

Steve
 
heat4steve said:
I did not ask econoburn about wiring. The pumps are run through a relay which toggles between the circulator pump and the main pump. If you look at the wiring diagram for the econoburn the relay is fed with power through a 5 amp circuit breaker at terminal 11 and feeds either 14 (the circulator pump) when not energized or 12 (the primary pump) when the relay is energized. By hooking these connections to the single pump the pump will always operate. Note whenever the lighted swicth is turned on one of the lines is powered. Essentially the need for the relay is uncessary terminal 11 and the pump terminal could be directly wired. The need for the circulator pump makes no sense to me if a mixing valve is needed and note that Econoburn recommends use of a mixing valve. I posted this question back in November on this forum if you want to see more opinions. In addition, Mark at econoburn agreed with this assessment.

Concerning storage, I have two propane tanks stacked on top of each other with the top tank receiving the boiler supply. Just upstream of this location is a tee which the house supply draws off when needed. When the boiler is in operation the flow through the tanks will be from top to bottom. When heating with thermal storage the flow is in reverse - similar to the simple pressurized storage. Again my concern is that flow through the bypass may occurr when transitioning to heating with thermal storage until the Danfoss valve closes. From your diagram I think the flow would flow preferentially through the tank when heating with thermal storage.

I used 1-1/4" cooper and black pipe for my plumbing - could not bare spending for 1-1/2".

Steve

So which of my drawings are you referring to?

I have the econoburn 200 so from what I understand I really should use 1-1/2" for boiler to storage to move enough btu's at a low velocity.

gg
 
Your unit may need the larger pipe size. It all depends ont the DT you want to run the boiler at and the size of the pumo. Unfourtuantely Econoburn does no provide the flow resitance for the boiler so it is difficult to size the pump and pipe sizing. Can't go wrong with the larger size pipe.
 
Updated drawings, Removed the recirculation pump near Danfoss and Moved the Main boiler pump to just before the boiler on return side.

Suggestions?

gg
 

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With the Danfoss valve, the circulator can be placed as you show in the diagram or on the boiler supply just upstream of the bypass. Typically the circulator is placed just downstream of the expansion tank and the air separator to prevent cavitation and to keep air out of the pump. If the flow resistance between between the boiler supply and return is small this should not be an issue. But to follow best practice you would move the location of the expansion tank just upstream of the pump.
 
heat4steve said:
With the Danfoss valve, the circulator can be placed as you show in the diagram or on the boiler supply just upstream of the bypass. Typically the circulator is placed just downstream of the expansion tank and the air separator to prevent cavitation and to keep air out of the pump. If the flow resistance between between the boiler supply and return is small this should not be an issue. But to follow best practice you would move the location of the expansion tank just upstream of the pump.

I am confused, I could have swore that I have read multiple posts that you should pump away from expansion tank.

That is what confuses me about this whole setup. I am cursing the whole dang thing lately. Back to reading again.

gg
 
you should pump away from the exp tank so the exp. outlet should be before the pump, but keep the spirovent on the supply and put a plug on the bottom when using a mixing valve. I'm no expert but
did a little research and thats how the danfoss valve directions showed it when using a mixing valve.
 
Ok I understand the position now that it made it through my thick skull! I have been thinking about this way too much, it is clouding my brain.


The Danfoss pdf shows the pump on supply side, with other location at the boiler return.

gg
 
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